A police officer at the scene of an unrelated shooting in Phoenix in February. (AP Photo/Morry Gash)

(Newser)
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Six people have been shot—five fatally—within a four-mile radius in west Phoenix's Maryvale neighborhood since April. Now police say a serial killer (or killers) may be on the loose. Authorities have made little progress in the investigation but say all six victims—aged 12 to 32—were shot outside their homes or near their cars on weekend evenings. Though there is no apparent motive in any of the shootings, physical evidence connects them, police sources say without elaborating. Diego Verdugo-Sanchez, 21, appears to have been the first victim, shot outside his fiance's family home while locking his car door around 9pm on April 1, reports NBC News. Then on June 3, Horacio de Jesus Pena, 32, was killed just feet from his car after returning home from work at 9:50pm, reports the Arizona Republic.

A week later, Manuel Castro Garcia, 19, was shot dead while outside his home at 9:30pm. Two days after that, on June 12, two women and a girl were outside a home around 3am when shots were fired. Angela Linner, 31, and Maleah Russell, 12, were killed. Maleah's mother, Stefanie Ellis, remains at a hospital in critical condition. Police say they have little to go on as witnesses have given varying descriptions of possible suspects. No personal connections have been uncovered between the victims. "There's been no activity, very few tips" despite a $11,000 reward for information leading to an arrest, says an officer. "For not one person to have more information is mind-blowing," says Pena's twin sister. Police say extra officers are patrolling the streets, while a volunteer group known as the Guardian Angels is also keeping watch, per KPNX.